748 M. W. R. de V. GRAHAM 



the three tergites following the basal one nearly always with some trace of 

 alutaceous sculpture in their basal part . . . acuminatus sp. n. (p. 762) 



Head (Text-fig. 626) 1-07-1 -15 times as broad as the mesoscutum. Marginal 

 vein 1-18-1-45 times as long as the stigmal vein. Gaster acute but not 

 acuminate apically ; last tergite slightly shorter than its basal breadth ; 

 the three tergites following the basal one are smooth peregrinus sp. n. (p. 764) 



36 (34) Antenna (Text-fig. 637) with scape reaching above the level of the vertex, 



and virtually as long as an eye. Body elongate ; gaster lanceolate, 

 slightly longer than head plus thorax, fully twice as long as broad. Pro- 

 podeum almost as long as scutellum, its median area about as long as 

 broad. Fore wing with marginal vein about twice as long as the stigmal 

 vein ......... scaposus sp. n. (p. 774) 



— Antenna (Text-fig. 639) with scape not reaching above the level of the 



vertex, somewhat shorter than an eye. Body more squat ; gaster not 

 longer than head plus thorax, usually ovate, rarely lanceolate. Propodeum 

 about three quarters as long as the scutellum, its median area at least 

 slightly broader than long. Fore wing with marginal vein sometimes 

 shorter relative to the stigmal vein . . . . . . -37 



37 (36) Eyes relatively smaller, separated by 1-3-1-4 times their length ; malar 



space half or virtually half the length of an eye. Antenna (Text-fig. 639) 

 with first funicular segment distinctly shorter than the second, slightly to 

 distinctly transverse. Fore wing with marginal vein 1-4-1-75 times as 

 long as the stigmal vein ......... 38 



Eyes relatively larger, separated by only 1-1-1-25 times their length ; malar 

 space 0-35-0-4 the length of an eye. Antennae with first funicular segment 

 usually as long as the second, rarely very slightly shorter. Fore wing with 

 marginal vein sometimes longer relative to the stigmal vein ... 39 



38 (37) Left mandible with 3 teeth, right mandible with 4. Gaster 1-15-1-4 times as 



long as the thorax, 1-55-1-9 times as long as broad. Pronotal collar more 

 weakly and irregularly margined .... exiguus (Walker) (p. 770) 



- Both mandibles with 4 teeth. Gaster 1-0-1-05 times as long as the thorax, 



1-35-1-55 times as long as broad. Pronotal collar tending to be distinctly, 

 sometimes sharply, margined ..... maurus sp. n. (p. 770) 



39 (37) Fore wing with marginal vein only 1-3-1-4 times as long as the stigmal vein ; 



postmarginal vein as long as the marginal. 



Left mandible with 3 teeth, right mandible with 4 . sp. indet. E (p. 773) 

 Fore wing with marginal vein 1-7-2-25 times as long as the stigmal vein ; 



postmarginal vein often shorter than the marginal ..... 40 



40 (39) Left mandible with 3 teeth, right mandible with 4. Postmarginal vein nearly 



always at least slightly shorter than, rarely as long as, the marginal 



hemipterus (Walker) (p. 771) 

 Both mandibles with 4 teeth. Postmarginal vein as long as or virtually as 

 long as the marginal. (Possibly an aberrant form of hemipterus) 



sp. indet. F (p. 773) 



41 (1) Gaster (Text-fig. 596) : the first four tergites have a transverse row of hairs, 



and also at least some trace of alutaceous sculpture. Propodeum (Text- 

 fig. 596) with plicae indistinct or nearly absent in the front half of the 

 sclerite ; callus with only a row of short hairs next to the edge of the meta- 

 pleuron, and a very few isolated hairs above the supracoxal flange. 

 (North America) ....... subapterus (Riley) (p. 776) 



Gaster : the first four tergites are bare except laterally ; the basal tergite, and 

 sometimes the three following ones, smooth, Propodeum with plicae 

 distinct throughout ; callus with more numerous, and longer, hairs. 



